Step-by-step explanation:
Given.
![3x+5y=3](https://tex.z-dn.net/?f=3x%2B5y%3D3)
![x+2y=0](https://tex.z-dn.net/?f=x%2B2y%3D0)
Take the second equation and subtract 2y to both sides.
![(x+2y)-2y=0-2y](https://tex.z-dn.net/?f=%28x%2B2y%29-2y%3D0-2y)
![x=-2y](https://tex.z-dn.net/?f=x%3D-2y)
Substitute x into the first equation and simplify.
![3x+5y=3](https://tex.z-dn.net/?f=3x%2B5y%3D3)
![3(-2y)+5y=3](https://tex.z-dn.net/?f=3%28-2y%29%2B5y%3D3)
![-6y+5y=3](https://tex.z-dn.net/?f=-6y%2B5y%3D3)
![-y=3](https://tex.z-dn.net/?f=-y%3D3)
Invert.
![y=-3](https://tex.z-dn.net/?f=y%3D-3)
Substitute Y into your second equation.
![x+2y=0](https://tex.z-dn.net/?f=x%2B2y%3D0)
![x+2(-3)=0](https://tex.z-dn.net/?f=x%2B2%28-3%29%3D0)
![x-6=0](https://tex.z-dn.net/?f=x-6%3D0)
Add -6 to both sides.
![(x-6)+6=0+6](https://tex.z-dn.net/?f=%28x-6%29%2B6%3D0%2B6)
![x=6](https://tex.z-dn.net/?f=x%3D6)
Answer:
(6, -3)
Answer:
12.5
Step-by-step explanation:
f of x just means y, so you're just finding y when x = 1/2
Answer:
h = 8 feet
Step-by-step explanation:
see attached
Answer:
8
Step-by-step explanation:
Let's just call the number x for simplicity.
So, 7x is 8 less than x².
Putting this into an equation would look like this
x² - 8 = 7x
It looks like we'll have to factor this to solve. Before we do that we need to move the 7x to the left side so that everything is together.
x² - 7x -8 = 0
Now, we can proceed. To factor we first need to find the factors of -8.
The factors of -8 are
-2 ⋅ 4, -4 ⋅ 2, -1 ⋅ 8, 1 ⋅ -8.
We need to find the pair of factors that adds up to -7. The only ones that do are -1 and 8.
So now that we have these we can create a pair of binomials using them. This will give us the factored form of this equation.
( x + 1 ) ( x - 8 )
To find the solutions we will have to set them to 0 and solve each of these binomials individually.
x - 1 = 0
x = 1
So, one of the solutions is 1. It's not the one we want, since it's positive.
x - 8 = 0
x = 8
This is the one we want since it is positive.